Removable cylinder liners for internal combustion engines



April 1957 G. DE cam-z DE CASTELET 3,315,573

REMOVABLE CYLINDER LINERS FOR INTERNAL COMBUSTION ENGINES Filed March 26, 1965 Gaeiah De Coye Decasiglet' 5 ja flmwww Inventor United States Patent 3,315,573 REMOVABLE CYLINDER LINERS FOR INTERNAL COMBUSTION ENGINES Gaetan de Coye de Castelet, Billancourt, France, assignor to Regie Nationale des Usines Renault, Seine, France, a French works Filed Mar. 26, 1965, Ser. No. 442,913 Claims priority, application France, Apr. 1, 1964, 969,400, Patent 1,398,868 1 Claim. (Cl. 92-171) This invention relates to removable cylinder liners for internal combustion engines, and more particularly to liners intended for light-metal cylinder block castings.

Removable liners resorted to heretofore are made of a ferrous metal throughout, the coefficient of expansion of which is very much less than that of the light metal. As a result, when the engine temperature rises they lengthen much less than does the housing in which they are positioned. Hence, when the engine is hot, the cylinder head, which is rigidly connected to the cylinder, tends to separate from the upper face of the liner. This in turn causes a tendency for gas leaks to take place from the cylinder to the cooling water, resulting in rapid destruction of the cylinder-head gasket. Under low temperature conditions, on the contrary, because the cylinder block contracts more than do the liners, water leaks tend to take place.

It is the object of the present invention to overcome these drawbacks.

Removable liners according to the invention comprise an active ferrous-metal portion in contact with the piston and a light-metal belt which is moulded upon the ferrous metal and surrounds said active portion in perfect adhesion thereto. This belt extends from the cylinder-head end of the liner over a length substantially equal to the piston stroke. Preferably, said belt extends over the entire portion included between the cylinder-head end of the liner and a ridge located closer to the other end, said ridge being formed on the ferrous-metal portion of the liner and bearing against a corresponding surface on the cylinder block.

Alternatively, liners may be devised in which this ridge is dispensed with, in which case the light-metal belt would bear directly against the cylinder block 7.

The belt is rendered integral with the active portion of the liner by any convenient method, whereby the surfaces in mutual contact can in no case slip relatively to each other.

In liners according to the present invention, the degree of expansion of the inset portion of the liner, between its cylinder-block thrust point and its end adjacent the cylinder head is intermediate the degrees of expansion it would undergo were it to be made entirely of ferrous metal and entirely of light metal, respectively. Of course, the aim is to cause this expansion to be as close as possible to that of light metal by reducing to a minimum the thickness of the ferrous metal forming the inset portion.

In this way, the difference in elongation under heat between the inset part of the liner and the cylinder is considerably reduced and can be absorbed by deformation of the parts Without jeopardizing the integrity of the cylinder-head gasket.

3 ,3 l5 ,5 73 Patented Apr. 25, 1 967 A liner according to the invention will now be more particularly described with reference to the accompanying non-limitative exemplary drawing, in which:

FIGURE 1 shows a first possible embodiment of a ridged liner, and

FIGURE 2 shows a less liner.

The liner shown in section in FIGURE 1 consists of an active ferrous-metal portion 1 whose bore 2 is in contact with the piston (not shown) and possesses the desirable frictional qualities. This ferrous metal portion has formed thereon a ridge 3 adapted to bear against a corresponding surface provided on the liner-lodging in the cylinder block.

Over the portion 4 included between the ridge 3 and its end section 5 adjacent the cylinder head 8, the ferrous metal is surrounded by a light-metal belt 6 moulded thereon and caused, by any method well-known per se, to closely hug the ferrous metal.

Once the liner has been fitted into the cylinder block 7, it is restrainedtherein between said ridge and the cylinder head 8, with a conventional cylinder head gasket 9 being positioned between said head and said block.

Referring next to FIGURE 2, the liner shown thereon comprises the same parts as that of FIGURE 1, but the active ferrous-metal portion 1 is n'dgeless. The liner bears against the cylinder block as at 13, against the terminal portion of the light-metal belt 6.

What is claimed is:

A removable liner for internal combustion engines more particularly for engines comprising a cylinder block cast form a light metal and onto which a cylinder head is fixed and inside of which pistons slide, said liner comprising an active ferrous metal cylindrical segment, said cylindrical segment having a length greater than the piston stroke and being mounted in said cylinder block and contacting said piston, a light metal belt molded on the exterior of said ferrous metal cylindrical segment to adhere perfectly thereto, said light metal belt extending over the entire cylindrical segment included between the end adjacent the cylinder head and a ridge formed on the segment in such a manner that, once the light metal belt has been fitted, the liner is restrained in the cylinder block between the cylinder head and a surface corresponding to said ridge and provided in the cylinder block, said light metal belt bearing directly against a corresponding surface in the cylinder block at a point adjacent said cylinder head, said light metal belt having a length substantially equal to the length of the pistonstroke whereby the relative expansion between said liner and said cylinder block is kept to a minimum.

possible embodiment of a ridge- References Cited by the Examiner MARTIN P. SCHWADRON, Primary Examiner. I. C. COHEN, Assistant Examiner. 

